If you had the choice between a premium chocolate truffle for 15 cents or a Hershey’s Kiss for a penny, which would you choose?

If you’re like most people (75%), you’ll gladly splurge on the truffle. 

Now, consider a different scenario. The prices have been discounted by a penny each: You can buy the premium chocolate truffle for 14 cents, or get a Hershey’s Kiss for free.

Astonishingly, 69% of people will opt for the Hershey’s Kiss simply because it’s free. How could something as insignificant as a penny determine whether people enjoy a rare delicacy versus a chunk of foil-covered sugar you can find in any checkout aisle?

These are the questions Dan Ariely explores in Predictably Irrational: The Hidden Forces That Shape Our Decisions.

Most of us fancy ourselves as savvy decision-makers, capable of seeing through finely crafted sales pitches, advertising slogans, and faulty advice. But as Ariely reminds us, the human brain is a flawed instrument that drives us to behave in ways contradicting our self-interest—often without us knowing about it.

From planning meals to planning vacations, buying candy bars to houses, we consistently overpay, underestimate, and procrastinate – and we can’t help it. Horrifying! 

But there’s good news: Our misguided behaviors are neither random nor senseless. As Ariely notes, they’re systematic and predictable—they make us “predictably irrational.”

At the risk of sounding too Zen-like, admitting you don’t have total control of your thoughts and behaviors gives you more control than the person who’s convinced they never make mistakes. Keeping that in mind, here are three key takeaways from Predictably Irrational that can untangle the wires in your brain:  

Put important decisions and habits on autopilot: This is like a cheat code for beating procrastination. For example, we help clients set up automatic savings plans to avoid the “I’ll do that someday” trap.

Remember to be suspicious of “free”: The prospect of getting something for nothing is powerful. Truthfully though, everything comes with a price tag. A free lunch might be used as leverage for a favor down the road. You got “free” shipping because a pop-up told you to stuff your cart with items you don’t want or need. Our encouragement? Try getting curious about how you are paying for any “free” item offered to you. It might help you make more informed choices.  

Strategically reduce your choices: Sounds counterintuitive, but when people have too many options, they freeze up and make suboptimal decisions. But the antidote isn’t learning to make better decisions—it’s eliminating the ones that don’t matter. At Hill Investment Group, we boil down decades of research to give clients only the relevant information.

We’ve come across plenty of books about behavioral economics that are mind-numbingly complex and laden with jargon. This isn’t one of them. Ariely’s writing is as informative as an academic lecture and isn’t boring.

Once you dive into this book, you’ll never make decisions the same way again.